Touch pads and touch screens are input devices for operating a device. With a touch pad, such as touch pads on a personal laptop computer, the movement of the input pointer on a display generally corresponds to the relative movements of the user's finger as the finger is moved along a surface of the touch pad. Touch screens are a type of display screen that can include a touch-sensitive transparent panel that overlays the display screen. When using a touch screen, a user typically makes a selection on the display screen by pointing directly to objects (such as GUI objects) displayed on the screen.
In both of these cases, the user moves one or more fingers on a two-dimensional surface to operate the device. However, for the operation of many devices, it is desirable, preferable or even necessary for the user to move his or her fingers over a three-dimensional surface. Thus, there is a need for enabling multi-touch inputs and gestures in the operation of such devices.